Earth formations may be used for various purposes such as hydrocarbon production, geothermal production, and carbon dioxide sequestration. In order to efficiently use an earth formation, the formation is characterized by performing measurements of many different properties. One type of measurement is formation resistivity or its inverse conductivity. Resistivity measurements may be performed by a resistivity logging tool that is disposed in a borehole penetrating the formation. In logging-while-drilling applications, the logging tool is connected to a drill string and the measurements are performed while the borehole is being drilled.
Induction resistivity measurements may be performed by transmitting electromagnetic signals into a formation from a transmitter antenna and receiving corresponding electromagnetic signals that were modified by the formation with a receiver antenna. The received signals include information that is used to determine the formation resistivity. The receiver antenna and the transmitter antenna, while connected to the same drill string, are spaced a distance from each other. Unfortunately, as the borehole is being drilled, the drill pipes making up the drill string can undergo torsion and bending causing the alignment between the transmitter antenna and the receiver antenna to change. The misalignment and bending introduce an additional angle between transmitter and receiver such that they are no longer in the original alignment, which produces parasitic coupling and associated signals. These parasitic signals make it difficult or impossible to acquire any reliable directional measurements including direction and distance to bed or resistivity anisotropy measurement. Accordingly, any change in the alignment, either from bending and/or torsion, can cause the resistivity data to be corrupted or loose accuracy. Hence, it would be well received in the drilling and geo-physical exploration industries if resistivity logging tools could be improved to correct for drill string torsion and bending.